JP5130853B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus.

2. Description of the Related Art Conventionally, ink jet type image recording apparatuses capable of recording images on both sides of a recording medium are known. Regarding this type of image recording apparatus, the following Patent Document 1 discloses that a sheet 5 having an image formed on one side is stopped on a flat lower guide plate 170A disposed on the downstream side of the recording head 24. A technique is described in which the stopped paper 5 is restrained from above and below by the conveying rollers 71, 171-173 and the spurs 72, 174-176 opposed thereto, so that the paper 5 is not easily curled. ing.
Japanese Patent Laying-Open No. 2006-82546 (paragraph “0105, FIG. 1 etc.)

  However, in the technique described in Patent Document 1 described above, it is necessary to install a flat lower guide plate 170A on the downstream side of the recording head 24 in order to make it difficult for the paper 5 to be curled. Invite Further, in addition to the lower guide plate 170A, it is necessary to mount a conveying roller 71, a spur roller 72, and the like for restraining the paper 5, and there is a problem that the configuration in the apparatus becomes complicated.

  SUMMARY An advantage of some aspects of the invention is to provide an image recording apparatus capable of correcting a recording medium with a simple configuration without increasing the size of the apparatus. Yes.

  In order to achieve this object, an image recording apparatus according to claim 1 is in contact with a recording medium stacked on a tray and feeds the recording medium, and feeds from the feeding roller. And a recording head for recording an image by ejecting ink onto the recording medium, and the recording head can record an image on both the front surface and the back surface of the recording medium. The recording medium that is disposed downstream and sandwiches the recording medium that has passed through the recording head, and again faces the sheet feeding roller so that the surface of the recording medium on which an image is recorded by the recording head contacts the sheet feeding roller. A pair of feeding rollers, a pair of feeding rollers, and a path for a back surface that branches from a path connecting the pair of feeding rollers and the recording head and extends toward the paper feeding roller, and a downstream side of the path for the back surface. A path formed with a U-shaped curved portion toward the recording head, and the recording medium is conveyed so that the surface opposite to the surface with which the paper feed roller contacts is opposed to the recording head. And the recording medium transported in the paper feeding path by the paper feeding roller after the image is recorded on the front surface of the recording medium and before the image is recorded on the back surface of the recording medium. After the recording medium is stopped in a U-shape for a first predetermined time and an image is recorded on the surface of the recording medium, the recording medium is transferred to the back surface path by the pair of feed rollers. , And before reaching the paper feed roller again, stop means for stopping the recording medium for a second predetermined time, and recording that has been stopped in the paper feed path by the stop means for the first predetermined time. How to proceed out of the medium The amount of ink ejected to the first area from the leading edge to the abutting area where the paper feed roller abuts, and the second area from the abutting area to the trailing edge in the traveling direction of the recording medium. Detecting means for detecting the amount of ejected ink, and a first drying time required for the first area to dry in accordance with the amount of ink ejected to the first area detected by the detecting means; A calculation unit that calculates a second drying time required for the second region to dry according to the amount of ink ejected to the second region detected by the detection unit, and a calculation unit that calculates the second drying time required for the second region to dry On the condition that the second drying time is longer than the first drying time, the difference time between the second drying time and the first drying time is not more than the first predetermined time. Determination means for determining whether or not the stop means, When the recording medium is stopped as the first predetermined time as the second predetermined time, and the determination unit determines that the difference time is equal to or shorter than the first predetermined time, the first area When the recording medium is stopped for the first predetermined time in the paper feed path at the time when the paper passes the paper feed roller, and it is determined that the difference time is longer than the first predetermined time, When the first area passes the paper feed roller, the recording medium is stopped for the difference time in the paper feed path.
The image recording apparatus according to claim 2 is the image recording apparatus according to claim 7, wherein one of the pair of feed rollers that contacts the surface of the recording medium first is the other feed roller. This is a driven roller that is rotated by being driven, and is rotatably supported by one end of the driven roller so as to be rotatable about the rotation axis of the other feed roller. A path switching arm that abuts the recording medium and guides the recording medium sandwiched between the pair of feed rollers from the leading end located on the upstream side to the back surface path; the path switching arm; A paper guide for supporting a recording medium that is disposed upstream of the recording path and downstream of the recording head and that supports the recording medium that has passed through the recording head. The pair The recording medium is temporarily stopped in a state where the recording medium is sandwiched between the feeding rollers and the other end side is supported by the paper guide, and the paper guide and the pair of feeds among the stopped recording media are then stopped. In a state where the portion positioned between the rollers is pressed by the path switching arm and bent in a V shape from the front surface side of the recording medium toward the back surface path, the recording medium is Stop for a predetermined time.
The image recording apparatus according to claim 3 is in contact with the recording medium loaded on the tray, and discharges ink to the recording medium fed from the paper feeding roller. A pair of recording heads that are capable of recording images on both the front and back surfaces of the recording medium with the recording heads, and are disposed downstream of the recording heads. A feed roller, which is composed of one feed roller that first contacts the surface of the recording medium and a driven roller that rotates following the other feed roller, and sandwiches the recording medium that has passed through the recording head. A pair of feed rollers that convey the recording medium on which an image is recorded by the recording head toward the paper feed roller again so that the surface of the recording medium contacts the paper feed roller, and the pair of feed rollers And a path for the back surface that branches from the path connecting the recording head and extends toward the paper feed roller, and a curved portion is formed in a U shape from the downstream side of the path for the back surface toward the recording head. Of the pair of feed rollers, and a driven path of the pair of feed rollers, and a path that conveys the recording medium such that a surface opposite to the surface on which the sheet feed roller abuts is opposed to the recording head A roller is rotatably supported at one end side and extends upstream, and is configured to be rotatable about the rotation shaft of the other feed roller. The other end abuts the recording medium, and the pair of feeds A path switching arm that guides the recording medium sandwiched between the rollers from the leading end located on the upstream side to the path for the back surface, and upstream of the path switching arm and the back surface path, and Arranged downstream of the recording head A paper guide that supports the recording medium that has passed through the recording head, and after the image is recorded on the front surface of the recording medium and before the image is recorded on the back surface, In a state where the recording medium being conveyed is deformed in a U shape in the curved portion, the recording medium is stopped for a first predetermined time, and an image is recorded on the surface of the recording medium. After the recording medium is temporarily stopped in a state where one end side of the recording medium is sandwiched between the pair of feed rollers and the other end side is supported by the paper guide, the paper among the stopped recording media In a state where a portion positioned between the guide and the pair of feed rollers is pressed by the path switching arm and bent in a dogleg shape from the front side of the recording medium toward the back path, Stop means for stopping the recording medium for a second predetermined time.
According to a fourth aspect of the present invention, there is provided the image recording apparatus according to the third aspect, wherein from the leading end portion in the advancing direction of the recording medium that is stopped in the paper feed path by the stop unit for the first predetermined time. According to the detection means for detecting the amount of ink discharged to the first area up to the contact portion with which the paper feed roller is in contact, and the amount of ink discharged to the first area detected by the detection means, Calculating means for calculating a first drying time required for the first region to dry, and the stopping means stops the first drying time as the second predetermined time, and the recording medium, When the first area passes the paper feed roller, the recording medium is stopped in the paper feed path for the first predetermined time.

According to another aspect of the image recording apparatus of the present invention, the recording medium loaded on the tray is fed by the feed roller and passes through the feed path formed in a U shape at the curved portion. The image is recorded on the surface by the recording head. Then, the recording medium on which the image is recorded is conveyed to the sheet feeding roller so that the surface contacts the sheet feeding roller, and is again conveyed into the sheet feeding path by the sheet feeding roller. In a state where the curved portion is deformed into a U-shape, it is stopped by the stopping means for a first predetermined time. Therefore, the recording medium is subjected to curling by receiving a pressing force in the inner direction through the paper feed path. Accordingly, when the recording medium is transported from the paper feed path to a position facing the recording head, the recording medium is smoothly transported between the recording head and the platen, and the curling is not performed. Can be prevented from occurring between the platen and the platen. In addition, the curl brazing is performed by stopping the recording medium in a U-shaped state in the paper feed path for a first predetermined time. There is no need to mount the configuration, and there is an effect that the recording medium can be corrected with a simple configuration without increasing the size of the apparatus.
The recording medium on which the image is recorded is sandwiched between a pair of feed rollers disposed downstream of the recording head, and the pair of feed rollers causes the surface on which the image is recorded to be a feed roller. It is conveyed in the back surface path so as to come into contact.

The recording medium on which an image is recorded on the surface, before reaching again the sheet feeding roller through the back plane for path is stopped a second predetermined time by the stop means. Therefore, it is possible to secure a drying time for drying the surface of the recording paper before the surface of the recording medium comes into contact with the paper feed roller, and the surface of the recording medium comes into contact with the paper feed roller. There is an effect that it is possible to suppress the transfer of the image recorded on the paper feeding roller.

Also, among the first predetermined time stop to have a recording medium in the sheet feed path by the stop means, from the traveling direction front end portion to abutment sheet feeding roller is in contact with the first region, the first region The amount of ink ejected to the first area is detected by the detecting means, and the first drying time required for the first area to dry is calculated by the calculating means according to the detected amount of ink ejected to the first area. . Further, from the contact portion where the paper feed roller is in contact to the rear end portion in the traveling direction as the second region, the amount of ink ejected to the second region is detected by the detection means, and the detected second region is detected. The second drying time required for the second region to dry is calculated by the calculation means in accordance with the amount of ejected ink. Then, first, the recording medium is a second predetermined time, the first drying time, Ru is stopped by the stop means. Therefore, it is possible to reliably prevent the image recorded in the first area from being transferred to the paper feed roller . Whether the difference between the second drying time and the first drying time is equal to or shorter than the first predetermined time on condition that the second drying time is longer than the first drying time. When it is determined by the determining means and it is determined that the difference time is equal to or shorter than the first predetermined time, the recording medium is stopped by the stopping means in the sheet feeding path when the first area passes the sheet feeding roller. When it is determined that the difference time is longer than the first predetermined time, the recording medium is stopped by the stop means in the paper feed path when the first area passes the paper feed roller. The That is, if the difference time is equal to or shorter than the first predetermined time, the second drying time necessary for drying the second region has already passed. It is not necessary to stop the recording medium until the drying time elapses. The image recorded on the second area is restrained from being transferred to the paper feed roller, and the image is printed on both sides of the recording medium at high speed. There is an effect that it can be recorded. On the other hand, when the difference time is longer than the first predetermined time, the second drying time necessary for drying the second area has not yet elapsed, and therefore the recording medium until the difference time elapses. By stopping the operation, it is possible to suppress the image recorded in the second area from being transferred to the paper feed roller.

According to the image recording apparatus according to claim 2, in addition to the effects of the image recording apparatus according to claim 1, of the pair of feed rollers, one feed roller abutting the surface of previously recording medium, the other The stop means temporarily stops the recording medium in a state where one end side of the recording medium is sandwiched between the pair of feeding rollers and the other end side is supported by the paper guide. After that, when the path switching arm that rotatably supports the driven roller on one end side and extends upstream is rotated around the rotation axis of the other feed roller, the other end side of the path switching arm is stopped. The recording medium abuts on a portion located between the paper guide and the pair of feed rollers. As a result, the recording medium is bent in a dogleg shape from the front surface side toward the back surface path, and the stop means stops the recording medium in this state for a second predetermined time. Therefore, the curl can be attached to the recording medium, the recording medium is suppressed from being lifted, the rear end (front end of the back surface) is easily guided to the paper feed roller, and the recording medium has an image recorded on the surface. There is an effect that it is possible to prevent a jam from occurring due to the leading end of the sheet colliding with the paper feed roller.
According to another aspect of the image recording apparatus of the present invention, the recording medium loaded on the tray is fed by the feed roller and passes through the feeding path formed in a U shape at the curved portion, and the recording head. The image is recorded on the surface by the recording head. Then, the recording medium on which the image is recorded is conveyed to the sheet feeding roller so that the surface contacts the sheet feeding roller, and is again conveyed into the sheet feeding path by the sheet feeding roller. In a state where the curved portion is deformed into a U-shape, it is stopped by the stopping means for a first predetermined time. Therefore, the recording medium is subjected to curling by receiving a pressing force in the inner direction through the paper feed path. Accordingly, when the recording medium is transported from the paper feed path to a position facing the recording head, the recording medium is smoothly transported between the recording head and the platen, and the curling is not performed. Can be prevented from occurring between the platen and the platen. In addition, the curl brazing is performed by stopping the recording medium in a U-shaped state in the paper feed path for a first predetermined time. There is no need to mount the configuration, and there is an effect that the recording medium can be corrected with a simple configuration without increasing the size of the apparatus.
The recording medium on which the image is recorded is sandwiched between a pair of feed rollers disposed downstream of the recording head, and the pair of feed rollers causes the surface on which the image is recorded to be a feed roller. It is conveyed in the back surface path so as to come into contact. Further, the recording medium having the image recorded on the front surface is stopped by the stop means for a second predetermined time before passing through the back surface path and reaching the paper feed roller again. Therefore, it is possible to secure a drying time for drying the surface of the recording paper before the surface of the recording medium comes into contact with the paper feed roller, and the surface of the recording medium comes into contact with the paper feed roller. There is an effect that it is possible to suppress the transfer of the image recorded on the paper feeding roller.
According to the image recording apparatus of the fourth aspect, in addition to the effect achieved by the image recording apparatus of the third aspect, the traveling direction of the recording medium stopped in the paper feed path for the first predetermined time by the stopping unit. The amount of ink ejected to the first area is detected by the detection means from the leading end to the abutting portion where the paper feed roller is abutted, and the detected ink amount is ejected to the first area. Accordingly, the first drying time required for the first region to dry is calculated by the calculating means. Then, the recording medium is stopped by the first drying time and stopping means as the second predetermined time, and is stopped in the paper feed path for the first predetermined time when the first region passes the paper feed roller. Therefore, it is possible to reliably prevent the image recorded in the first area from being transferred to the paper feed roller, and to pass the paper feed roller while the recording medium is stopped for the first predetermined time. The portion of the recording medium that has not been dried can be dried, and by combining the stop time for curling and the stop time for drying, images can be recorded on both sides of the recording medium at high speed. .

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an external perspective view of a multifunction machine 10 according to an embodiment of the present invention. The multifunction machine 10 includes an inkjet printer unit 11 that can record images on both sides of a recording sheet, which is an example of a recording medium, and corrects the recording sheet with a simple configuration without increasing the size of the apparatus. It is something that can be done.

  The multifunction machine 10 has various functions such as a telephone call function, a facsimile function, a printer function, a scanner function, and a copy function. The printer function includes a double-sided printing function for recording an image on both sides of a recording sheet. Have.

  The multifunction machine 10 is mainly provided with a printer unit 11 provided in the lower part, a scanner part 12 provided in the upper part, an operation panel 40 provided in the upper part of the front, and a slot part 43 provided in the front. .

  The printer unit 11 has an opening 13 formed in the front, and a paper feed tray 20 and a paper discharge tray 21 are provided in two upper and lower stages so that a part of the opening 13 is exposed. The paper feed tray 20 is for loading recording paper. The recording paper loaded on the paper feed tray 20 is fed into the printer unit 11 and is discharged to the paper discharge tray 21 after a desired image is recorded.

  The scanner unit 12 is configured as a so-called flat bed scanner. The document cover 30 is provided as a top plate of the multifunction machine 10, and a platen glass (not shown) is disposed under the document cover 30. The document is placed on the platen glass and read by the scanner unit 12 while being covered with the document cover 30.

  The operation panel 40 is for operating the printer unit 11 and the scanner unit 12 and is provided with various operation buttons and a liquid crystal display unit. The user can set various functions and perform operations by operating the operation panel 40. For example, setting of the type of recording paper (plain paper or postcard) as a recording medium, setting of single-sided recording mode for recording an image only on the surface of the recording paper, setting of double-sided recording mode for recording an image on both front and back sides, resolution The setting of (draft mode or photo mode) can be instructed via the operation panel 40.

  The slot portion 43 is configured to be loaded with various small memory cards that are storage media. For example, when the user operates the operation panel 40 with the small memory card loaded in the slot unit 43, the image data stored in the small memory card is read, and the read image data is recorded on the recording paper. be able to.

  Next, the configuration of the printer unit 11 will be outlined with reference to FIG. FIG. 2 is a longitudinal sectional view showing the structure of the printer unit 11. The printer unit 11 mainly includes a feeding unit 15 that feeds recording paper to the conveyance path 23, a conveyance path 23 that conveys recording paper fed from the feeding unit 15, and the conveyance path 23. A recording unit 24 that records an image on a recording sheet by ejecting ink droplets onto the conveyed recording sheet, a discharge tray 21 on which the recording sheet is discharged, and between the discharge tray 21 and the recording unit 24. A path switching unit 41 that is arranged and switches the path of the recording sheet to record an image on the back surface, and a reversal that guides the recording sheet whose path is switched by the path switching unit 41 to the feeding unit 15 and the conveyance path 23 side. A guide 16 is provided.

  The feeding unit 15 is provided with a paper feed tray 20 on which recording paper is stacked. The paper feed tray 20 is disposed on the bottom side of the printer unit 11 and is configured in a box shape with an open top surface. The recording paper loaded on the paper feed tray 20 is fed to the transport path 23 by the paper feed roller 25.

  When an image is recorded on one side (front surface) of the recording paper, the recording paper fed by the paper feed roller 25 is guided and recorded so as to make a U-turn from below to above along the transport path 23. The image is recorded on the surface by the recording unit 24 and then discharged to the paper discharge tray 21.

  On the other hand, when images are recorded on both sides (front and back) of the recording paper, the reversing guide portion is arranged by the path switching portion 41 so that the recording paper with the image recorded on the front surface comes into contact with the paper feed roller 25. 16, the paper is fed again to the conveyance path 23 by the paper feed roller 25, and the image is recorded on the back surface of the recording medium by the recording unit 24, and then discharged to the paper discharge tray 21.

  Next, the configuration of the printer unit 11 will be described in detail with reference to FIG. FIG. 3 is a partially enlarged sectional view of the printer unit 11.

  In the feeding unit 15, a paper feed roller 25 is disposed above the paper feed tray 20. The paper feed roller 25 feeds the recording paper loaded on the paper feed tray 20 to the transport path 23, and is rotatably supported at the tip of the paper feed arm 26. The paper feed roller 25 is rotationally driven via a power transmission mechanism 27 using an LF motor 71 (see FIG. 9) as a drive source. The drive transmission mechanism 27 includes a plurality of gears arranged in a straight line, and is configured by meshing them.

  The paper feed arm 26 has a base end portion supported by a base shaft 28 and is configured to be rotatable about the base shaft 28 as a rotation center axis. For this reason, the paper feed arm 26 can move up and down so as to be able to contact and separate from the paper feed tray 20. Further, the paper feed arm 26 is urged to rotate downward by its own weight or urged by a spring or the like. For this reason, the sheet feeding arm 26 is normally configured to come into contact with the sheet feeding tray 20 and retract upward when the sheet feeding tray 20 is inserted and removed.

  When feeding recording paper from the paper feed tray 20, the paper feed arm 26 is biased downward and the paper feed roller 25 is pressed against the recording paper on the paper feed tray 20. By rotating the paper roller 25, the uppermost recording paper is fed out to the separation inclined plate 22 by the frictional force generated between the roller surface of the paper feeding roller 25 and the recording paper.

  When the leading edge of the recording sheet comes into contact with the separation inclined plate 22, the recording sheet is guided upward and sent to the conveyance path 23 along the arrow 14. When the uppermost recording paper is sent out by the paper feed roller 25, the recording paper immediately below it may be sent out together by friction or static electricity, but this recording paper is restrained by contact with the separation inclined plate 22. Is done.

  The conveyance path 23 is formed so as to be bent upward in a U-shape from the separation inclined plate 22 to the front side, and from the back side (left side in FIG. 3) to the front side (right side in FIG. 3). And extends to the paper discharge tray 21 via the recording unit 24.

  The conveyance path 23 is defined by an outer guide surface and an inner guide surface except for a portion where the recording unit 24 or the like is disposed. For example, the curved portion 17 of the conveyance path 23 on the back side of the multifunction machine 10 is formed by fixing the outer guide member 18 and the inner guide member 19 to the main body frame 53. In this case, the outer guide member 18 forms an outer guide surface, and the inner guide member 19 forms an inner guide surface. Moreover, the outer side guide member 18 and the inner side guide member 19 are opposingly arranged at predetermined intervals.

  A rotating roller 29 is provided at a location where the conveyance path 23 is bent. The rotating roller 29 is configured to be rotatable, and the roller surface of the rotating roller 29 is exposed to the outer guide surface. Therefore, the recording paper is smoothly transported even at the portion where the transport path 23 is bent.

  The recording unit 24 is disposed in the middle of the conveyance path 23 and includes a carriage 38 and a recording head 39. The recording head 39 is mounted on the carriage 38 and is configured to reciprocate along the guide rails 105 and 106 in the main scanning direction (the vertical direction in FIG. 3).

  Specifically, the carriage 38 is slid through a belt drive mechanism, for example, using a CR motor 95 (see FIG. 9) as a drive source. Note that an ink cartridge (not shown) is disposed inside the multi-function device 10 independently of the recording head 39. Ink is supplied from the ink cartridge to the recording head 39 through an ink tube. Then, while the carriage 38 is reciprocated, ink is ejected as fine ink droplets from the recording head 39, whereby an image is recorded on the recording paper conveyed on the platen 42.

  The main body frame 53 of the multifunction machine 10 is provided with a linear encoder 85 (see FIG. 9) that detects the position of the carriage 38. An encoder strip of the linear encoder 85 is disposed on the guide rails 105 and 106. The encoder strip includes a light transmitting portion that transmits light and a light shielding portion that blocks light, and the light transmitting portion and the light shielding portion are alternately arranged at a predetermined pitch in the longitudinal direction of the encoder strip to form a predetermined pattern. doing.

  An optical sensor 107 that is a transmissive sensor is provided on the upper surface of the carriage 38. The optical sensor 107 is provided at a position corresponding to the encoder strip, reciprocates along the longitudinal direction of the encoder strip together with the carriage 38, and detects the pattern of the encoder strip during the reciprocation.

  Further, the carriage 38 is provided with a media sensor 86 (see FIG. 9) that detects the presence or absence of a recording sheet on the platen 42. The media sensor 86 includes a light source and a light receiving element, and light emitted from the light source is applied to the recording paper conveyed on the platen 42 while the recording paper is not conveyed to the platen 42. Is irradiated to the platen 42. Then, the light irradiated on the recording paper or the platen 42 is reflected, and the light receiving element receives the reflected light, and outputs according to the amount of light received.

  A transport roller 60 and a pinch roller 31 are provided on the upstream side of the transport path 23 from the recording unit 24. These are paired, and the pinch roller 31 is disposed so as to be in pressure contact with the lower side of the conveying roller 60. The conveying roller 60 and the pinch roller 31 are for holding the recording paper conveyed through the conveying path 23 and feeding it onto the platen 42.

  Further, a discharge roller 62 and a spur roller 63 are provided on the downstream side of the conveyance path 23 from the recording unit 24. The paper discharge roller 62 and the spur roller 63 sandwich the recorded recording paper and transport it further from the transport path 23 to the downstream side in the transport direction (to the paper discharge tray 21 side).

  The transport roller 60 and the paper discharge roller 62 are driven using the LF motor 71 as a drive source, and the drive of the transport roller 60 and the paper discharge roller 62 are synchronized and are intermittently driven during image recording. As a result, the recording sheet is image-recorded while being sent with a predetermined line feed width.

  The transport roller 60 is provided with a rotary encoder 87 (see FIG. 9). The rotary encoder 87 detects a pattern of an encoder disk (not shown) that rotates together with the conveyance roller 60 with an optical sensor, and the rotation of the conveyance roller 60 and the discharge roller 62 is performed based on a signal detected by the optical sensor. Be controlled. In addition, before and after image recording, the transport roller 60 and the paper discharge roller 62 are continuously driven to realize rapid paper transport.

  The spur roller 63 presses the recorded recording paper, and the spur roller 63 has a spur-like unevenness on the roller surface so that the image recorded on the recording paper does not deteriorate. The spur roller 63 is provided so as to be slidable in a direction in which the spur roller 63 is in contact with and separated from the paper discharge roller 62, and is urged so as to be in pressure contact with the paper discharge roller 62. As a means for urging the spur roller 63 against the paper discharge roller 62, a coil spring is typically employed.

  Although not shown in FIG. 3, in the present embodiment, a plurality of spur rollers 63 are provided, and each spur roller 63 is equally in the direction orthogonal to the recording paper conveyance direction, that is, the width direction of the recording paper. It is installed side by side. The number of spur rollers 63 is not particularly limited, but is set to 8 in this embodiment.

  When the recording paper enters between the paper discharge roller 62 and the spur roller 63, the spur roller 63 retracts against the biasing force of the coil spring by the thickness of the recording paper. The recording paper is pressed against the paper discharge roller 62, and the rotational force of the paper discharge roller 62 is reliably transmitted to the recording paper. Similarly, the pinch roller 31 is also elastically biased with respect to the conveying roller 60. Therefore, the recording sheet is pressed against the conveying roller 60, and the rotational force of the conveying roller 60 is reliably transmitted to the recording sheet.

  A registration sensor 102 (see FIG. 9) is provided on the upstream side of the transport path 23 from the transport roller 60. The registration sensor 102 includes a detector and an optical sensor. The detector is arranged so as to cross the transport path 23 and can appear and disappear in the transport path 23. The detector is elastically biased so as to always protrude into the transport path 23, and the detector is immersed in the transport path 23 when the recording paper transported through the transport path 23 contacts the detector. The optical sensor is turned on or off by the appearance of the detector. Therefore, the position of the leading edge or the trailing edge of the recording paper in the transport path 23 is detected by causing the recording paper to make the detector appear and disappear.

  Next, the route switching unit 41 will be described with reference to FIGS. 4 and 5. 4 and 5 are enlarged sectional views showing the periphery of the route switching unit in an enlarged manner. FIG. 5 shows a state in which the route switching unit 41 in the state shown in FIG. 4 is rotated about the central axis 52 as a rotation center. Show.

  The path switching unit 41 is disposed on the downstream side of the recording unit 24. Specifically, the path switching unit 41 is disposed downstream of the recording unit 24 in the downstream portion 36 of the transport path 23, that is, on the downstream side in the transport direction at the boundary portion between the transport path 23 and the reverse guide unit 16. The path switching unit 41 is provided with a first roller 45 and a second roller 46 constituting a roller pair, and an auxiliary roller 47 arranged in parallel with the second roller 46.

  The first roller 45 and the second roller 46 sandwich the recording paper 103 sent from the paper discharge roller 62 and the spur roller 63. The first roller 45 and the second roller 46 can transport the recording paper 103 along the transport path 23 further downstream in the transport direction (to the paper discharge tray 21 side) and transport the recording paper to the reversal guide unit 16. Is possible.

  The second roller 46 and the auxiliary roller 47 are attached to the frame 48. The frame 48 extends in the left-right direction of the multi-function device 10 (the direction perpendicular to the plane of FIG. 3) (see FIG. 6). The cross-sectional shape of the frame 48 is formed in a substantially L shape, thereby ensuring the required bending rigidity of the frame 48.

  The frame 48 includes eight integrated subframes 49 (see FIG. 6). Each sub-frame 49 is symmetrically arranged in the left-right direction with respect to the center of the multifunction machine 10. Each subframe 49 pivotally supports one second roller 46 and auxiliary roller 47. Therefore, each frame 48 includes eight second rollers 46 and auxiliary rollers 47, and each second roller 46 and auxiliary roller 47 has a direction orthogonal to the recording sheet conveyance direction, that is, the recording sheet 103. Are arranged in parallel in the width direction.

  The second roller 46 and the auxiliary roller 47 are pivotally supported by support shafts 50 and 51 provided in each sub-frame 49 and are configured to be rotatable around the support shafts 50 and 51. In the present embodiment, the second roller 46 and the auxiliary roller 47 are formed in a spur shape. The auxiliary roller 47 is disposed upstream of the second roller 46 by a predetermined distance in the transport direction. Each second roller 46 is urged downward by a spring (not shown) and is always elastically pressed against the first roller 45.

  The first roller 45 is connected to the LF motor 71 via a required drive transmission mechanism, and is driven to rotate using the LF motor 71 as a drive source. The first roller 45 includes a central shaft 52, and the central shaft 52 is supported on the main body frame 53 side of the multifunction machine 10.

  A second roller 46 is placed above the first roller 45. The first roller 45 may be formed in a single elongated cylindrical shape, and eight rollers may be arranged to face the second rollers 46, respectively.

  The first roller 45 is configured to be forwardly and reversely rotated by the LF motor 71 so that the recording sheet can be conveyed to the discharge tray 21 side and the reverse guide unit 16 side. That is, the recording sheet 103 conveyed along the conveyance path 23 is sandwiched between the first roller 45 and the second roller 46. When the first roller 45 rotates forward, the recording sheet 103 is conveyed downstream in the conveying direction while being sandwiched between the first roller 45 and the second roller 46 and is discharged to the paper discharge tray 21. On the other hand, when the first roller 45 rotates in the reverse direction, the recording sheet is returned to the upstream side in the transport direction while being sandwiched between the first roller 45 and the second roller 46.

  In the present embodiment, the outer diameter of the first roller 45 is set slightly larger than the outer diameter of the paper discharge roller 62. That is, when both are driven at the same rotational speed, the peripheral speed of the first roller 45 is larger than the peripheral speed of the paper discharge roller 62. Therefore, when the recording paper 103 is conveyed by both the paper discharge roller 62 and the first roller 45, the recording paper 103 is always pulled in the conveyance direction.

  Here, the drive mechanism 44 of the path switching unit 41 configured as described above will be described with reference to FIGS. FIG. 6 is a perspective view of the path switching unit 41. FIG. 7 is a view in the direction of arrow VII shown in FIG. 8 is a view taken in the direction of arrow VIII shown in FIG. The drive mechanism 44 is for driving the path switching unit 41 from the state shown in FIG. 4 to the state shown in FIG. 5 or for returning from the state shown in FIG. 5 to the state shown in FIG.

  As shown in FIG. 6, the drive mechanism 44 includes a driven gear 54 provided on the central shaft 52, a drive gear 55 that meshes with the driven gear 54, and a cam 57 that is connected to the drive gear 55.

  The cam 57 is connected to one end of a rotation drive shaft 58, and the rotation drive shaft 58 is driven using the LF motor 71 as a drive source. As shown in FIG. 8, the cam 57 is provided with a guide groove 59. The guide groove 59 is formed in an annular shape around the rotation drive shaft 58. Specifically, the guide groove 59 includes a small arc portion 69 and a large arc portion 70 centered on the rotation drive shaft 58, and a connection groove 72 that connects one end of the small arc portion 69 and one end of the large arc portion 70. A connecting groove 73 that connects the other end of the small arc portion 69 and the other end of the large arc portion 70 is provided.

  As shown in FIGS. 6 and 7, the driven gear 54 includes a tooth portion 64 and a flange portion 65. The tooth portion 64 is configured as an involute gear centered on the central shaft 52. The tooth portion 64 is fitted into the central shaft 52 and can rotate around the central shaft 52. The flange portion 65 is formed integrally with the tooth portion 64 and is connected to the frame 48. Therefore, when the tooth portion 64 rotates, the frame 48, the sub frame 49, the second roller 46, and the auxiliary roller 47 rotate integrally with the central shaft 52 as the rotation center.

  The drive gear 55 is rotatably supported on the support shaft 66. The support shaft 66 is provided on the main body frame 53. The drive gear 55 includes a tooth portion 67 and an arm 68. The tooth portion 67 is configured as an involute gear centered on the support shaft 66 and meshes with the tooth portion 64. A pin 56 shown in FIG. 8 protrudes from the arm 68, and the pin 56 is fitted in the guide groove 59 and is slidable along the guide groove 59. Then, when the tooth portion 67 rotates, the tooth portion 64 rotates, and as a result, the frame 48, the sub-frame 49, the second roller 46, and the auxiliary roller 47 rotate integrally around the center shaft 52 as a rotation center.

  As shown in FIG. 8, when the cam 57 rotates, the pin 56 moves relatively along the guide groove 59, and particularly when sliding along the connecting grooves 72, 73, the pin 56 moves toward the cam 57. It will move in the radial direction. For this reason, when the cam 57 is rotated clockwise (in the direction of the arrow 82) in FIG. 8, the pin 56 sequentially moves to the large arc portion 70, the connecting groove 72, and the small arc portion 69.

  Accordingly, the drive gear 55 rotates clockwise in FIG. As a result, the driven gear 54 rotates counterclockwise around the central axis 52 in FIG. As described above, since the driven gear 54 is connected to the frame 48, the rotation of the driven gear 54 causes the frame 48, the sub frame 49, the first roller 46, and the auxiliary roller 47 to rotate around the central shaft 52. Rotates integrally. From this state, if the cam 57 rotates in the reverse direction as described above, the frame 48, the sub-frame 49, the first roller 46, and the auxiliary roller 47 rotate as a whole with the central shaft 52 as the center of rotation. , Return to the original state.

  In this embodiment, when the posture of the path switching unit 41 as shown in FIG. 4 is “recording medium discharge posture” and the posture of the path switching unit 41 as shown in FIG. When an image is recorded only on the surface of the recording sheet (single-sided recording), the path switching unit 41 is always in the recording medium discharge posture, and the recording sheet conveyed along the conveyance path 23 is left as it is. (See FIG. 4).

  On the other hand, when the path switching unit 41 changes to the recording medium reversal posture, the recording paper 103 is guided to the reversal guide unit 16 as shown in FIG. Specifically, when images are recorded on both the front and back sides of the recording paper, first, the path switching unit 41 maintains the recording medium ejection posture (see FIG. 4), and the recording paper on which the image is recorded is transported in the transport direction. Sent downstream. Thereafter, the path switching unit 41 changes from the recording medium discharge posture (see FIG. 4) to the recording medium reverse posture (see FIG. 5), and the auxiliary roller 47 presses the recording paper 103 and guides it to the reverse guiding unit 16 side. .

  Returning again to FIG. 4, the description will be continued. A guide unit 76 is disposed on the downstream side of the path switching unit 41 configured as described above. The guide portion 76 is provided on the downstream side in the transport direction with respect to the first roller 45 and the second roller 46. A support plate 75 is attached to the main body frame 53, and a guide portion 76 is provided on the support plate 75.

  The guide portion 76 is provided with a base portion 77 fixed to the lower surface of the support plate 75 and a guide roller 78 supported by the base portion 77. The base 77 includes a support shaft 79, and the guide roller 78 is rotatably supported by the support shaft 79. In the present embodiment, the guide roller 78 is formed in a spur shape.

  The guide unit 76 contacts the recording surface of the recording sheet 103 when the first roller 45 and the second roller 46 are rotated in the reverse direction and the recording sheet 103 is sent to the reverse guiding unit 16. Further, the guide unit 76 does not contact the recording sheet 103 when the first roller 45 and the second roller 46 are rotated forward and the recording sheet 103 is sent to the reverse guide unit 16. Specifically, the guide portion 76 is provided at a position where it does not come into contact with an imaginary line connecting the contact point between the first roller 45 and the second roller 46 and the contact point between the paper discharge roller 62 and the spur roller 63.

  When the recording paper 103 is sent to the reversing guide unit 16 while changing the direction of the conveyance direction, a portion of the recording paper 103 downstream of the first roller 45 and the second roller 46 is caused by the rigidity of the recording paper 103. It acts to change the direction in a direction parallel to the reversing guide portion 16. However, the guide roller 78 comes into contact with the recording surface of the recording paper 103 and bends the recording paper 103. Accordingly, since the recording paper 103 is wound around the first roller 45 and the second roller 46, a stable conveying force can be obtained, and the recording paper 103 is surely sent to the reverse guide unit 16.

  Returning again to FIG. 3, the description will be continued. The reversing guide unit 16 is connected to the conveyance path 23 and is continuous to the downstream portion 36 of the conveyance path 23 relative to the recording unit 24. The reversing guide unit 16 constitutes a reversing path that guides the recording paper having an image recorded on the surface thereof onto the paper feed tray 20 again. This inversion path is defined by the first guide surface 32 and the second guide surface 33.

  In the present embodiment, the first guide surface 32 and the second guide surface 33 are formed by the surfaces of the guide member 34 and the guide member 35 disposed inside the main body frame 53 of the multifunction machine 10, respectively. The guide members 34 and 35 are arranged to face each other at a predetermined interval, and the first guide surface 32 and the second guide surface 33 are obliquely downward from the downstream portion 36 of the transport path 23 toward the paper feed roller 25. It extends to.

  In the present embodiment, the reversing guide unit 16 is configured to return the recording paper onto the paper feed tray 20, but is not limited thereto. In short, it is sufficient for the reversing guide unit 16 to be able to connect the downstream side portion 36 and the upstream side portion 37 of the conveyance path 23, and therefore, the recording paper returns to the paper feed tray 20 side from the upstream side portion 37. It only has to be done.

  Next, the configuration of the control unit 84 of the multifunction machine 10 will be described with reference to FIG. FIG. 9 is a block diagram illustrating a configuration of the control unit 84 of the multifunction machine 10. The control unit 84 controls the overall operation of the multifunction machine 10 including not only the printer unit 11 but also the scanner unit 12, but detailed description of the scanner unit 12 is omitted.

As shown in the figure, the control unit 84 includes a CPU (Central Processing Unit) 88, a ROM
(Read Only Memory) 89, RAM (Random Access Memory) 90, and an EEPROM (Electrically Erasable and Programmable ROM) 91 that stores settings and flags to be retained even after the power is turned off. The ASIC (Application Specific Integrated Circuit) 93 is connected via the bus 92.

  The ROM 89 stores a program for controlling various operations of the multifunction machine 10. For example, a print processing program 89a for executing the double-sided printing process shown in FIG. 10 is stored. The RAM 90 is used as a storage area or a work area for temporarily recording various data used when the CPU 88 executes the program.

  The ASIC 93 generates a phase excitation signal and the like for energizing the LF motor 71 in accordance with a command from the CPU 88, applies the signal to the drive circuit 94 of the LF motor 71, and sends the drive signal to the LF motor via the drive circuit 94. The rotation of the LF motor 71 is controlled by energizing the 71.

  The drive circuit 94 drives the LF motor 71 connected to the paper feed roller 25, the transport roller 60, the paper discharge roller 62, the first roller 45, etc., and receives the output signal from the ASIC 93 and receives the LF motor 71. An electric signal for rotating the is generated. In response to the electrical signal, the LF motor 71 rotates, and the rotational force of the LF motor 71 is fed via a known drive mechanism including a gear, a drive shaft, and the like, through the paper feed roller 25, the transport roller 60, the paper discharge roller 62, It is transmitted to the first roller 45.

  In this multifunction device 10, the LF motor 71 serves as a drive source for feeding recording paper from the paper feed tray 20, and transports recording paper that is positioned on the platen 42 and has already been recorded. Is a drive source for discharging the paper to the paper discharge tray 21, and further, a drive source for driving the paper discharge roller 62 via a predetermined power transmission mechanism.

  That is, the LF motor 71 drives the conveyance roller 60, the paper feed roller 25 via the drive transmission mechanism 27, and the paper discharge roller 62 via the predetermined power transmission mechanism. The predetermined power transmission mechanism may be constituted by a gear train, for example, or a timing belt or the like may be used due to the assembly space.

  Further, the ASIC 93 generates a phase excitation signal and the like for energizing a CR (carriage) motor 95 in accordance with a command from the CPU 88, gives the signal to the drive circuit 96 of the CR motor 95, and passes through the drive circuit 96. The CR motor 95 is controlled to rotate by energizing the CR motor 95 with a drive signal.

  The drive circuit 96 drives the CR motor 95 connected to the carriage 38, receives an output signal from the ASIC 93, and generates an electrical signal for rotating the CR motor 95. Upon receipt of the electrical signal, the CR motor 95 rotates, and the rotational force of the CR motor 95 is transmitted to the carriage 38, whereby the carriage 38 is reciprocated.

  The driving circuit 97 selectively ejects ink from the recording head 39 to the recording paper 103 at a predetermined timing, and receives an output signal generated by the ASIC 93 based on a driving control procedure output from the CPU 88. The drive of the recording head 39 is controlled.

The ASIC 93 includes a scanner unit 12, an operation panel 40 for instructing operation of the multifunction device 10, a slot unit 43 into which various small memory cards are inserted, an external device such as a personal computer, and data via a parallel cable or a USB cable. Are connected to a parallel interface (I / F) 98 and a USB interface (I / F) 99 for transmitting and receiving, an NCU (Network Control Unit) 100 and a modem (MODEM) 101 for realizing a facsimile function.

  In addition, the ASIC 93 includes a registration sensor 102 that detects that the recording paper 103 has been transported from the paper feed roller 25 to the vicinity of the transport roller 60, a rotary encoder 87 that detects the amount of rotation of each roller driven by the LF motor 71, and a carriage. A linear encoder 85 for detecting the amount of movement 38 and a media sensor 86 for detecting the presence or absence of the recording paper 103 on the platen 42 are connected.

  Here, a process performed by the control unit 84 of the multifunction machine 10 will be briefly described. When the power of the multifunction machine 10 is turned on, the carriage 38 is once moved to its slide end, and the detection position by the linear encoder 85 is initialized. When the carriage 38 slides from the initial position, the optical sensor 107 provided on the carriage 38 detects the encoder strip pattern.

  The control unit 84 grasps the movement amount of the carriage 38 based on the number of pulse signals based on the detection of the optical sensor 107, and controls the rotation of the CR motor 95 to control the reciprocation of the carriage 38 based on the movement amount. . Further, the control unit 84 grasps the position of the leading or trailing end of the recording paper 103 and the transport amount of the recording paper 103 based on the output signal of the registration sensor 102 and the encoder amount detected by the rotary encoder 87.

  When the leading edge of the recording paper 103 reaches a predetermined position of the platen 42, the control unit 84 controls the rotation of the LF motor 71 to intermittently convey the recording paper 103 for each predetermined line feed width. The line feed width is set based on the resolution input as the image recording condition. In particular, when high-resolution recording, specifically borderless photo recording, is performed, the control unit 84 is based on detection of the presence of the recording paper 103 by the media sensor 86 and the encoder amount detected by the rotary encoder 87. Detects the leading edge and trailing edge of the recording paper 103 accurately.

  Further, based on detection of the presence of the recording paper 103 by the media sensor 86 and the encoder amount detected by the linear encoder 85, the control unit 84 accurately detects the positions of both ends of the recording paper 103. The control unit 84 controls the ejection of ink droplets by the inkjet recording head 39 based on the positions of the leading edge, the trailing edge, and both ends of the recording paper 103 detected in this way.

  Next, a double-sided printing process executed by the CPU 88 of the multifunction machine 10 will be described with reference to FIG. FIG. 10 is a flowchart showing the duplex printing process executed by the CPU 88 of the multifunction machine 10. In the double-sided printing process of FIG. 10, a case where double-sided printing is instructed will be described. FIG. 11 is a plan view of the recording sheet 103 facing the front side. 12 to 15 are cross-sectional views showing the state of the recording paper 103 during double-sided printing in chronological order.

  In this double-sided printing process, when a print execution instruction is input, the paper feed roller 25 is driven to transport the recording paper 103 from the paper feed tray 20 into the transport path 23 along the direction of the arrow 14. In the conveyance path 23, the recording paper 103 is reversed so that the surface (front surface) opposite to the surface with which the paper feeding roller 25 contacts is opposed to the nozzle formation of the recording head 39.

  When the recording paper 103 reaches the conveying roller 60 and the pinch roller 31, the recording paper 103 is sandwiched by the conveying roller 60 and the pinch roller 31, and the recording paper 103 is moved between the recording head 39 and the platen by the conveying roller 60 and the pinch roller 31. The image recording on the surface facing the recording head 39 is started. When image recording on the surface is started, detection of the amount of ink discharged on the surface is started (S1).

  Here, with reference to FIG. 11, detection of the amount of ink discharged to the surface will be described. FIG. 11 is a plan view of the recording sheet 103 facing the front side. In FIG. 11, the direction in which the recording medium is conveyed between the recording head 39 and the platen 42 is shown as the sub-scanning direction, and the lower end of the recording sheet 103 in the figure is the front end (back end). The upper end of the recording paper 103 in the drawing is shown as the rear end of the front surface (the front end of the back surface). Further, in the recording sheet 103, an area from the rear end of the front surface to the distance L1 in the sub-scanning direction is a first area R1, and the remaining area (an area from the front end to the distance L2 in the anti-sub-scanning direction) is a second area R2. As shown.

  The distance L1 in the sub-scanning direction from the front surface rear end (back surface front end) is from the front surface rear end (back surface front end) to the surface of the recording paper 103 at the secondary stop position of the recording paper 103 described later (see FIG. 14E). This is the distance to the rear end (see the two-dot chain line in the figure) of the paper feed roller 25 that abuts.

  Then, as the ink discharge amount discharged to the surface, the ink discharge amount discharged to the first region R1 and the ink discharge amount discharged to the second region R2 are detected. In the present embodiment, the amount of ink ejected to the first region R1 and the amount of ink ejected to the region R2 are detected by the number of ejections of ink ejected to each region. However, the method for detecting the ink discharge amount is not limited to this, and for example, the ink discharge amount may be detected from the ink consumption amount and the data amount.

  Returning again to FIG. 10, the description will be continued. When the recording of the image on the surface and the detection of the ink amount are started, the recording paper 103 is intermittently conveyed by the conveying roller 60 and the pinch roller 31, and the carriage 38 is slid and recorded while the recording paper 103 is stopped. An image is recorded on the surface of the recording paper 103 by the head 39.

  When the recording paper 103 reaches the paper discharge roller 62 and the spur roller 63, the paper discharge roller 62 and the spur roller 63 are driven, and the recording paper 103 is conveyed further downstream by the paper discharge roller 62 and the spur roller 63. Further, when the recording paper 103 reaches the first roller 45 and the second roller 46, the first roller 45 and the second roller 46 are driven, and the recording paper 103 is further moved downstream by the first roller 45 and the second roller 46. Transport. During this time, the image recording on the surface of the recording paper 103 and the detection of the ink discharge amount are completed (S2).

  Then, when the image recording on the surface is finished, the first drying time T1 necessary for drying the first region R1 according to the ink discharge amount discharged to the first region R1 and the second region R2, and A second drying time T2 necessary for drying the second region R2 is calculated (S3).

  Then, as shown in FIG. 12A, the recording paper 103 is sandwiched between the first roller 45 and the second roller 46, and the upstream end extends to the downstream side of the paper discharge roller 62. The recording paper 103 is conveyed by the first roller 45 and the second roller 46 to the first stop position where the surface 32 is supported, and the driving of the first roller 45 and the second roller 46 is stopped at the first stop position. (S4).

  Thereafter, as shown in FIG. 12A, the path switching unit 41 is changed so that the path switching unit 41 in the recording medium discharge attitude is changed to the recording medium holding attitude as shown in FIG. 12B. Is driven (S5). In the present embodiment, as shown in FIG. 12B, the recording medium holding posture means that the path switching unit 41 is moved to the recording medium discharge posture (see FIG. 4 and FIG. This is a posture rotated to an intermediate position with respect to the recording medium reversal posture (see FIGS. 5 and 13C).

  When the path switching unit 41 is changed from the recording medium discharge attitude shown in FIG. 12A to the recording paper holding attitude shown in FIG. 12B, the path is switched around the support shaft 50 of the first roller 45. The part 41 is rotated. That is, the second roller 46 rolls on the circumferential surface of the first roller 45 while holding the recording paper 103, and the auxiliary roller 47 directs the recording paper 103 from the surface side of the recording paper 103 toward the reverse guide portion 16. And press.

  Then, after the path switching unit 41 is changed to the recording medium holding posture shown in FIG. 12B, the first drying time T1 is stopped in that state (S6).

  Accordingly, a drying time for drying the first region R1 of the recording paper 103 can be secured before the first region R1 of the recording paper 103 contacts the paper feed roller 25, and the first region R1 of the recording paper 103 is secured. Is in contact with the paper feed roller 25, it is possible to prevent the image recorded in the first region R 1 of the recording paper 103 from being transferred to the paper feed roller 25.

  In addition, as shown in FIG. 12B, the recording sheet 103 is bent in a V shape from the surface side of the recording sheet 103 toward the reverse guide unit 16 by the auxiliary roller 47 of the path switching unit 41. Since the first drying time T1 is stopped in this state, the recording paper 103 can be curled. Therefore, the recording paper 103 is suppressed from being lifted, the rear end (front end of the back surface) of the front surface is easily guided to the paper feed roller 25, and the front end of the recording paper 103 on which an image is recorded is the paper feed roller 25. It is possible to suppress the occurrence of jam by colliding with

  Thereafter, when the first drying time T1 has elapsed, as shown in FIG. 12 (b), the path switching unit 41 in the recording medium holding posture is changed to the recording medium inversion posture as shown in FIG. 13 (c). The path switching unit 41 is driven so as to be changed (S7).

  When the path switching unit 41 is changed to the recording medium reversing posture, the path switching unit 41 is rotated around the central axis 52 of the first roller 45 as described above, and the recording is further performed by the auxiliary roller 47. The paper 103 is pressed. As a result, the recording paper 103 is pressed by the auxiliary roller 47 from the front side toward the reverse guide unit 16, and the recording paper 103 is positioned at the leading end located upstream of the recording paper 103 as shown in FIG. (The rear end of the front surface and the front end of the back surface) enter the reversing guide portion 16 side.

  Then, the first roller 45 and the second roller 46 are driven in reverse to convey the recording paper 103 toward the paper feed roller 25 in the reverse guide unit 16 (S8). Thereafter, as shown in FIG. 13D, when the leading end portion (the rear end of the front surface and the front end of the back surface) of the recording paper 103 reaches the paper feed roller 25, the paper feed roller 25 is driven (S9).

  However, the paper feed roller 25 is driven after a lapse of a predetermined time after the recording paper 103 reaches the paper feed roller 25, and during this time, the first roller 45 and the second roller 46 are continuously reversed. Thereby, the skew of the recording paper 103 is adjusted, and the refeeding property by the paper feed roller 25 can be improved.

  The paper feed roller 25 is driven, and the recording paper 103 is deformed into a U shape in the transport path 23 by the paper feed roller 25 and the first roller 45 and the second roller 46 as shown in FIG. The recording paper 103 is conveyed to the second stop position where the state is set, and the driving of the paper feed roller 25, the first roller 45, and the second roller 46 is stopped at the second stop position (S10).

  Then, it is determined whether the difference time (T2−T1) between the second drying time T2 and the first drying time T1 is equal to or shorter than a preset time T3 as a time for stopping the recording paper 103 at the second stop position. If it is determined that the difference time (T2-T1) is equal to or shorter than the set time T3 (S11: Yes), the recording paper 103 is stopped at the second stop position for the set time T3 (S12).

  This set time T3 is a time required for curling the recording paper 103, and when the set time T3 is stopped in a state where the recording paper 103 is deformed in a U shape in the transport path 23, the recording paper 103 is loaded. A desired curl can be attached.

  As a result, the recording paper 103 can be introduced into the conveyance roller 60 and the pinch roller 31 without causing a jam, and the recording paper 103 can be smoothly conveyed between the recording head 39 and the platen 42. Further, this curling is performed by stopping the set time T3 in a state where the recording paper 23 is deformed in a U-shape in the conveyance path 23. It is not necessary to mount a configuration, and the curl can be attached to the recording paper 103 with a simple configuration without increasing the size of the apparatus. Further, while the recording paper 103 is stopped for the set time T3, the second region R2 of the recording paper 103 that has not passed through the paper feed roller 25 can be dried. By combining the stop time for the printing, double-sided printing can be performed at high speed.

  On the other hand, if it is determined in S11 that the difference time (T2-T1) is longer than the set time T3 (S11: No), the recording paper 103 is stopped at the second stop position for the difference time (T2-T1). (S13). If the difference time (T2−T1) is equal to or shorter than the set time T3, the second drying time T2 necessary for drying the second region R2 has already passed. It is not necessary to stop the recording paper 103 until the drying time T2 has elapsed, while suppressing the transfer of the image recorded in the second region R2 to the paper feed roller 25 and at a high speed. Images can be recorded on both sides.

  On the other hand, when the difference time (T2-T1) is longer than the set time T3, the second drying time T2 necessary for drying the second region R2 has not yet elapsed, so the difference time (T2- By stopping the recording paper 103 until T1) elapses, it is possible to suppress the image recorded in the second region R2 from being transferred to the paper feed roller 25.

  Thus, when the recording paper 103 is stopped at the second stop position for the set time T3 or the difference time (T2-T1), thereafter, the recording paper 103 is fed in the conveyance path 23 as shown in FIG. The surface (back surface) opposite to the surface (front surface) with which the roller 25 abuts is reversed so as to face the nozzle formation of the recording head 39, and image recording is started by the recording head 39 on the back surface (S14).

  Then, as shown in FIG. 15G, before the leading edge (the leading edge of the back surface) of the storage sheet 103 enters the path switching unit 41, the path switching unit 41 is again moved from the recording medium reverse orientation to the recording medium. The path switching unit 41 is driven so as to change to the discharging posture (S15). Thereafter, image recording on the back surface of the recording paper 103 is completed (S16), and the recording paper 103 on which images are recorded on both sides is conveyed downstream in the conveying direction by the first roller 45 and the second roller 46. At this time, the first roller 45 and the second roller 46 rotate forward, and the recording paper 103 is discharged to the paper discharge tray 21 (S17).

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. Can be inferred.

  In the above-described embodiment, the case where the first region R1 and the second region R2 include the region that does not contact the paper feed roller 25 has been described. However, the first region R1 and the second region R2 are: You may comprise so that it may limit only to the area | region which contact | abuts the paper feed roller 25. FIG. In such a case, the range in which the ink discharge amount is detected is limited, the burden required to detect the ink discharge amount can be reduced, and the image recorded on the surface is not transferred to the paper feed roller 25. It is possible to grasp the drying time more accurately.

In addition, the stop time at the first stop position and the second stop position may be changed according to environmental conditions such as the type, temperature, and humidity of the recording paper 103. For example, in the case of the recording paper 103 having higher rigidity than plain paper, such as a postcard, it takes less time than the plain paper to add curl wrinkles. Therefore, the stop at the first stop position and the second stop position is required. In the case of the recording paper 103 having a shorter time than the plain paper and having a lower rigidity than the plain paper, such as a thin paper, it takes a longer time than the plain paper to apply the curl so that the first stop is performed. You may comprise so that the stop time in a position and a 2nd stop position may be made longer than a plain paper.
In addition, for example, the higher the humidity is, the more difficult it is to dry the ink. Therefore, the stop time at the first stop position and the second stop position is lengthened. Conversely, the lower the humidity is, the easier the ink is dried. You may comprise so that the stop time in a stop position and a 2nd stop position may be shortened. With this configuration, the curl can be more reliably attached and the transfer of the image to the paper feed roller 25 can be suppressed.

1 is an external perspective view of a multifunction machine according to an embodiment of the present invention. FIG. 3 is a longitudinal sectional view illustrating a structure of a printer unit of the multifunction machine. It is a partial expanded sectional view of a printer part. It is an expanded sectional view which expands and shows a route change part periphery. It is an expanded sectional view which expands and shows a route change part periphery. It is a perspective view of a path switching part. It is an arrow VII direction arrow line view shown in FIG. It is an arrow VIII direction arrow line view shown in FIG. FIG. 3 is a block diagram illustrating a configuration of a control unit of the multifunction machine. It is a flowchart which shows a double-sided printing process. FIG. 3 is a plan view of a recording sheet facing the front surface. It is sectional drawing which shows the state of the recording paper at the time of double-sided printing in time series order. It is sectional drawing which shows the state of the recording paper at the time of double-sided printing in time series order. It is sectional drawing which shows the state of the recording paper at the time of double-sided printing in time series order. It is sectional drawing which shows the state of the recording paper at the time of double-sided printing in time series order.

10 Multifunction machine (image recording device)
16 Reverse guide (rear path)
20 Paper tray (tray)
23 Transport path (paper feed path)
25 Feed roller 39 Recording head 45 First roller (a pair of feed rollers, the other roller)
46 Second roller (a pair of feed rollers, driven rollers)
49 Subframe (path switching arm)
103 Recording paper (recording medium)
S1 detection means S3 calculation means S6, S8 stop means S11 judgment means T1 first drying time (second predetermined time, first drying time)
T2 Second drying time (second drying time)
T3 set time (first predetermined time)
R1 first region R2 second region

Claims (4)

A sheet feed roller that contacts the recording medium loaded on the tray and feeds the recording medium; and a recording head that ejects ink onto the recording medium fed from the sheet feeding roller to record an image. In an image recording apparatus capable of recording images on both the front and back surfaces of the recording medium by the recording head,
The recording medium is disposed downstream of the recording head, sandwiches the recording medium that has passed through the recording head, and the surface of the recording medium on which an image is recorded by the recording head is again in contact with the paper feed roller. A pair of feed rollers transported toward the paper feed roller;
A back surface path branched from a path connecting the pair of feed rollers and the recording head and extending toward the paper feed roller;
What route Der formed a curved portion in a U-shape toward the recording head from the downstream side of the back surface for the path, opposed to the opposite face the recording head is the paper feed roller is abutted against the surface A paper feed path for conveying the recording medium,
After an image is recorded on the front surface of the recording medium and before an image is recorded on the back surface, the recording medium conveyed through the paper feed path by the paper feed roller is deformed into a U shape at the curved portion. The recording medium is stopped for a first predetermined time , and after the image is recorded on the surface of the recording medium, the recording medium is conveyed through the back surface path by the pair of feed rollers, and again Stop means for stopping the recording medium for a second predetermined time before reaching the paper feed roller;
Of the recording medium that has been stopped for the first predetermined time in the paper feed path by the stopping means, the recording medium is discharged to the first region from the leading end in the advancing direction to the contact portion with which the paper feed roller is in contact. Detecting means for detecting the ink amount and the amount of ink ejected to the second region from the contact portion to the rear end portion in the traveling direction of the recording medium;
In accordance with the amount of ink ejected to the first area detected by the detection means, the first drying time required for the first area to dry and the second area detected by the detection means are ejected. Calculating means for calculating a second drying time required for the second region to dry in accordance with the amount of ink remaining;
On the condition that the second drying time calculated by the calculating means is longer than the first drying time, the difference time between the second drying time and the first drying time is the first time. Determining means for determining whether the time is equal to or less than a predetermined time of 1,
The stopping means stops the recording medium for the first drying time as the second predetermined time, and when the determining means determines that the difference time is equal to or shorter than the first predetermined time. When the first region passes the paper feed roller, the recording medium is stopped in the paper feed path for the first predetermined time, and the difference time is determined to be longer than the first predetermined time. In this case, the image recording apparatus is characterized in that the recording medium is stopped for the difference time in the paper feed path when the first region passes the paper feed roller . Of the pair of feed rollers, one feed roller that first contacts the surface of the recording medium is a driven roller that rotates following the other feed roller,
The driven roller is rotatably supported at one end side and extends upstream, and is configured to be rotatable about the rotation shaft of the other feed roller. The other end abuts the recording medium, and the pair A path switching arm for guiding the recording medium sandwiched between the feeding rollers of the recording medium to a path for the back surface from a tip portion located on the upstream side;
A paper guide that is disposed upstream of the path switching arm and the back surface path and downstream of the recording head, and supports a recording medium that has passed through the recording head;
The stop means temporarily stops the recording medium in a state where one end side of the recording medium is sandwiched between the pair of feed rollers and the other end side is supported by the paper guide, and then stops. A portion of the recording medium positioned between the paper guide and the pair of feed rollers is pressed by the path switching arm into a V shape from the front side of the recording medium toward the back path. while being bent, an image recording apparatus according to claim 1, characterized in that said recording medium is stopped a second predetermined time. A sheet feed roller that contacts the recording medium loaded on the tray and feeds the recording medium; and a recording head that ejects ink onto the recording medium fed from the sheet feeding roller to record an image. In an image recording apparatus capable of recording images on both the front and back surfaces of the recording medium by the recording head,
A pair of feed rollers arranged on the downstream side of the recording head , comprising one feed roller that comes into contact with the surface of the recording medium and a driven roller that rotates following the other feed roller. A pair of the recording medium that has passed through the recording head and is conveyed toward the paper feeding roller again so that the surface of the recording medium on which an image is recorded by the recording head is in contact with the paper feeding roller. A feed roller,
A back surface path branched from a path connecting the pair of feed rollers and the recording head and extending toward the paper feed roller;
What route Der formed a curved portion in a U-shape toward the recording head from the downstream side of the back surface for the path, opposed to the opposite face the recording head is the paper feed roller is abutted against the surface A paper feed path for conveying the recording medium,
Of the pair of feed rollers, the driven roller is rotatably supported at one end side and extends upstream, and is configured to be rotatable around the rotation shaft of the other feed roller, and the other end side is the recording side. A path switching arm that abuts against the medium and guides the recording medium sandwiched between the pair of feed rollers from the front end located on the upstream side to the path for the back surface;
A paper guide that is disposed upstream of the path switching arm and the back surface path and downstream of the recording head, and supports a recording medium that has passed through the recording head;
After an image is recorded on the front surface of the recording medium and before an image is recorded on the back surface, the recording medium conveyed through the paper feed path by the paper feed roller is deformed into a U shape at the curved portion. The recording medium is stopped for a first predetermined time , and after an image is recorded on the surface of the recording medium, one end side of the recording medium is sandwiched between the pair of feed rollers, and the other end side is After the recording medium is temporarily stopped while being supported by the paper guide, a portion of the stopped recording medium located between the paper guide and the pair of feed rollers is while being bent from the front surface side of the recording medium is pressed against the shaped gradually toward the rear surface path by the path switching arm, and a stop means for the recording medium Ru stopped second predetermined time Being The image recording apparatus according to claim. Of the recording medium that has been stopped for the first predetermined time in the paper feed path by the stopping means, the recording medium has been discharged to the first area from the leading end in the advancing direction to the contact portion with which the paper feed roller is in contact. Detection means for detecting the amount of ink;
Calculating means for calculating a first drying time required for the first area to dry in accordance with the amount of ink ejected to the first area detected by the detecting means;
The stop means stops the recording medium for the first drying time as the second predetermined time, and puts the recording medium in the paper feed path when the first area passes the paper feed roller. The image recording apparatus according to claim 3 , wherein the image recording apparatus is stopped for a first predetermined time.

Images